This application relates to several operating parameters in a refrigerant cycle that are controlled by management of an economized cycle in a multi-circuit refrigerant system.
Refrigerant systems are utilized to condition (e.g., heat/cool) an environment. As is known, in a cooling mode a refrigerant cycle typically includes a compressor that compresses a refrigerant and delivers the refrigerant to a condenser. From the condenser, the refrigerant passes into an expansion device, and then downstream to an evaporator. From the evaporator, the refrigerant is returned to the compressor. In a heat mode, the flow is generally reversed.
One type of refrigerant cycle that improves efficiency, increases the capacity and provides additional control options to a designer, is an economizer cycle. In an economized refrigerant cycle, the refrigerant downstream of the condenser is split into two flows. The smaller of the two flows is expanded to reduce temperature of this tapped refrigerant, and then passed through an economizer heat exchanger. A main portion of the split flow also passes through the economizer heat exchanger. The expanded economizer flow cools the main refrigerant flow. When this main flow refrigerant reaches the evaporator, it thus has greater cooling capacity. The tapped refrigerant is typically returned to a compressor at an intermediate compression point downstream of the economizer heat exchanger.
While economized cycles do provide increasing capacity, they also provide options for additional control features. Many of these features have yet to be exploited.